1. Field of the Invention
Aspects of the present invention relate to Internet Protocol (IP) Multimedia Subsystem (IMS) voice calls. More particularly, aspects of the present invention relate to techniques for trunk optimization for IMS voice calls between an originating User Equipment (UE) and a terminating UE that are homed in a Circuit Switched (CS) network.
2. Description of the Related Art
Due to the coexistence of deployed 3rd Generation (3G) and 4th Generation (4G) wireless communication networks, it is possible to have 3G and 4G User Equipments (UEs) roaming from the 3G wireless communication network to the 4G wireless communication network and vice a versa. An example of the 3G wireless communication network is the Code Division Multiple Access (CDMA) 1x wireless communication network and an example of the 4G wireless communication network is the Long Term Evolution (LTE) wireless communication network.
The 3G wireless communication network and the 4G wireless communication network employ different types of network communications for voice calls. That is, the 3G wireless communication network employs Circuit Switched (CS) network communications for voice calls, and the 4G wireless communication network employs Packet Switched (PS) network communications for voice calls. However, regardless of whether the 3G and 4G UEs are roaming from one of the 3G and 4G wireless communication networks to the other of the 3G and 4G wireless communication networks, there is a need for voice calls to continue. This is a transitional requirement that remains until all UEs support 4G technologies. Accordingly, there is a need to implement techniques that address this transitional requirement.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as Prior Art with regard to the present invention.